Electromagnetic Linear Induction Pumps (EMPs) are an important research subject in the development of Gen IV sodium-cooled fast reactors. Especially, in the framework of the French Alternative Energies and Atomic Energy Commission’s (CEA) R&D program on the Advanced Sodium Technological Reactor for Industrial Demonstration (ASTRID), the use of an EMP on the secondary loop has been proposed because of its safety advantages compared to mechanical pumps. For nuclear safety reasons, it is needed to know the behavior of an Annular Linear Induction Pump (ALIP) at off-design conditions. Consequently, the present article is focused on the study of stalling magnetohydrodynamic (MHD) phenomenon occurring at the transition from linear to non-linear branch of the performance curve at the maximum of pressure. This phenomenon is associated to a consequent decrease of the pump efficiency and takes place at large magnetic Reynolds number (Rm).

Using a theoretical analytical model, we calculated the coupled base flow and magnetic field. Results permit to identify the stalling appearance for values of the Global slip magnetic Reynolds number (Rms) greater than 1. However, the corresponding parameter associated to the occurrence of this phenomenon does not match with numerical 2D-axisymmetrical model and experimental results.

For this reason, we have developed a geometry-simplified numerical model closer to the theoretical one. This simplified model presents slight defects, compared to the theoretical one, for the Rms limit of stalling. Anyway, this result shows the importance of simulating the real geometry in order to obtain a good estimate of stalling appearance.

Finally, using this analysis we have implemented improvements for the 3D numerical model under development, whose principal goal is the study of MHD azimuthal instabilities in an ALIP.